Morphine Sulfate

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MOR-feen SUL-fate - Pronunciation guide

Brand Names

  • Tramadol


Rx symbolMorphine sulfate appears as white odorless crystals that are soluble in water. Derived from opium, it is a naturally occurring opiate analgesic that is used to relieve moderate to severe pain and also as a pre-anesthetic agent for some surgical procedures.


Morphine sulfate is used as a narcotic analgesic to relieve moderate to severe pain, and also as a pre-anesthetic agent for some surgical procedures.

Dosage and Administration

Prescription medicationMorphine Sulfate
Method Dosage
(click row for calculator)
Concentration Period Duration
Slow Intravenous or Intramuscular injection 0.22 mg/kg 50 mg/ml Treatment NA
Slow Intravenous injection2 0.2-0.6 mg/kg 50 mg/ml Treatment NA


  • Federal law restricts this drug to use by or on the order of a licensed veterinarian.
  • Extra-label use of drugs in treating animals is allowable only by licensed veterinarians within the context of a valid veterinarian-client-patient relationship, and does not include drug use in treating animals by the layman (except under the supervision of a licensed veterinarian).
  • 1Use and administration of morphine sulfate should always occur under the supervision of a veterinarian because it is extremely difficult to determine the best dosage for each individual animal. All information on the manufacturer's insert should be read carefully before using morphine sulfate.
  • 2Premedicate with xylazine 1 mg/kg IV (Jenkins)
  • A wide variety of dose concentrations are available. Check label carefully.
  • Calculator is for educational purposes only. Follow your veterinarian's instructions regarding use of this, or any medication.

Side Effects

Narcotics such as morphine sulfate may cause central nervous system excitement in horses. Some veterinarians recommend pretreatment with acepromazine or xylazine to reduce the behavioral changes morphine can cause. Horses may exhibit signs of hyperthermia. They may also appear restless, and, at high doses, suffer convulsions.


Morphine sulfate may mask signs of colic and cardiovascular symptoms.

Morphine sulfate is a narcotic drug. Federal law restricts this drug to use by or on the lawful written or oral order of a licensed veterinarian.

Morphine sulfate would be prohibited in any sanctioned competition. Check with the proper regulatory board.


Other CNS depressants may cause increased CNS or respiratory depression when used with morphine.


Overdose may produce profound respiratory and central nervous system depression. Toxic effects can include cardiovascular collapse and skeletal muscle hypotonia. Naloxone is recommended to treat respiratory depression caused by overdose.


Winstron Depot Morphine Sulfate OralWinstron Depot Morphine Sulfate Oral



About the Author

EquiMed Staff

EquiMed staff writers team up to provide articles that require periodic updates based on evolving methods of equine healthcare. Compendia articles, core healthcare topics and more are written and updated as a group effort. Our review process includes an important veterinarian review, helping to assure the content is consistent with the latest understanding from a medical professional.